AU2021101392A4

AU2021101392A4 - Cable for charging piles for electric vehicles, preparation method thereof, and stranding device for weak-current flexible wire core

Info

Publication number: AU2021101392A4
Application number: AU2021101392A
Authority: AU
Inventors: Bin Cheng; Hongbin HUA; Jian Hua; Jingyi Wang; Linrui ZHANG
Original assignee: WUXISHI HUAMEI CABLE CO Ltd
Current assignee: Wuxishi Huamei Cable Co Ltd
Priority date: 2019-05-12
Filing date: 2021-03-17
Publication date: 2021-05-13
Anticipated expiration: 2028-04-09

Abstract

OF THE DISCLOSURE The invention provides a cable for charging piles for electric vehicles, a preparation method thereof, and a stranding device for a weak-current flexible wire core. A flexible wire core is formed by mixing and concentrically stranding aramid fibers and stainless steel wires, wherein the content of the aramid fibers is 80%-90%, and the pitch ratio is 5-10. The cable has good shielding performance and good bend resistance and heat resistance. 25 22 21 FIG. 2 2/5

Description

22

21

FIG. 2

2/5

CABLE FOR CHARGING PILES FOR ELECTRIC VEHICLES, PREPARATION METHOD THEREOF, AND STRANDING DEVICE FOR WEAK-CURRENT FLEXIBLE WIRE CORE BACKGROUND OF THE INVENTION

[0001] 1. Technical Field

[0002] The invention relates to the technical field of new energy vehicles, in

particular to a charging cable for charging piles.

[0003] 2. Description of Related Art

[0004] With the popularization and application of new energy vehicles,

particularly plug-in vehicles and pure electric vehicles, it is necessary to construct

charging piles like filling stations for traditional oil-fueled vehicles. The charging piles, as

the most direct ancillary equipment of electric vehicles, have developed vigorously, and

mainly relate to power conversion, charging control, billing and cable design, wherein the

power conversion, charging control and billing belong to software design, and only the

cable design belongs to hardware design. Cables for the charging piles are used not only

for transmitting electric energy, but also for transmitting data information, and typically

comprise electric power wire cores (strong-current wire cores) and weak-current wire

cores. The cables are often dragged, bent, crushed by vehicles, and even folded when

actually used for charging, and thus may be damaged, and particularly, the thin

weak-current wire cores may be damaged when the cables are crushed, and the

strong-current wire cores may be damaged when the cables are bent or folded. In view of

this, high requirements are put forward for the ductility, bend resistance, heat resistance,

crush resistance and other aspects of the cables.

[0005] In the prior art, many studies have been carried out on the bend resistance

of the cables, for example, the strong-current wire core is formed by combining a woven copper wire mesh and a multiple stranded wire to improve the bend resistance; or, the strong-current wire core is formed by extruding an elastomer insulation layer outside a conductor formed by stranding multiple separated flexible copper wires. All these methods can improve the bend resistance to some extent, but it is still possible and necessary to make some improvements on the weak-current wire cores and the strong-current wire cores of the charging cables to improve the shielding performance, bend resistance and high-temperature resistance of the wire cores. The flexible wire cores have an important influence on the quality of the cables. Traditionally, the flexible wire cores are prepared by mixing and stranding raw materials by manual control, which cannot guarantee the stranding tightness of the flexible wire cores and directly affects the using effect of the cables.

BRIEF SUMMARY OF THE INVENTION

[0006] The objective of the invention is to provide a cable for charging piles for

electric vehicles, which has good shielding resistance and good bend resistance.

[0007] To fulfill the above objective, the invention puts forwards the following

technical solutions:

[0008] A cable for charging piles for electric vehicles comprises: cable cores

including a charging cable core and a weak-current cable core, wherein the charging cable

core is configured as an electric energy transmission medium between charging piles and

electric vehicles, the weak-current cable core is configured as a signal cable core or a

control cable core of the same structure, and multiple charging cable cores and multiple

weak-current cable cores are distributed in a manner that every two of the charging cable

cores and the weak-current cable cores are tangent to each other;

[0009] A polyester belt layer wrapping the cable cores;

[0010] An overall shielding layer wrapping the polyester belt layer;

[0011] An isolation layer wrapping the overall shielding layer;

[0012] A braided layer wrapping the isolation layer; and

[0013] An outer sheath layer arranged outside the braided layer; and a filling layer

filled between the charging cable cores and the weak-current cable cores and wrapped

with the polyester belt layer;

[0014] Wherein, the weak-current cable core comprises a flexible wire core and a

copper wire wound around the flexible wire core, and the flexible wire core is formed by

mixing and concentrically stranding aramid fibers and stainless steel wires, wherein the

content of the aramid fibers is 80%-90%, and the pitch ratio is 5-10;

[0015] An insulation layer is extruded outside the copper wire;

[0016] The insulation layer is wrapped with a composite shielding layer braided

from metal wires and fibers;

[0017] The composite shielding layer is wrapped with a polyester belt layer;

[0018] The composite shielding layer comprises 60%-70% of metal wires, the

braiding angle is controlled to 45±5, the braiding density is greater than 80%, and the

thickness of the shielding layer is 0.3mm-0.5mm;

[0019] The charging cable core is formed by additionally braiding a layer of

silver-plated copper wires or tin-plated copper wires after multiple silver-plated copper

wires or tin-plated copper wires are stranded.

[0020] Preferably, the thickness of the polyester belt layer is 0.04-0.2mm.

[0021] Preferably, the insulation layer of the weak-current cable core is a silicone

rubber layer with high tear resistance, and has a thickness of 0.5-1mm.

[0022] Preferably, the isolation layer is a PVC isolation layer, or a PE or PO

isolation layer, and has a thickness of 0.8-2mm.

[0023] Preferably, the braided layer is an aramid braided layer, has a thickness of

0.3-0.5mm, and has a braiding density greater than 80%.

[0024] Preferably, the outer sheath layer is formed by extruding a PVC-rubber

mixture on the braided layer, and has a thickness of 1-3mm;

[0025] In the extrusion process of the outer sheath layer, the PVC-rubber mixture

is mixed with aluminum oxide or silicon carbide wear-resistant particles and graphite

powder, wherein the particle size of the wear-resistant particles is 40-60nm, and the

particle size of the graphite powder is 30-40nm.

[0026] According to an improved solution of the invention, a preparation method

of a cable for charging vehicles for electric vehicles is further provided and comprises the

following steps:

[0027] Step 1: preparing a charging cable core

[0028] Stranding multiple silver-plated copper wires or tin-plated copper wires and

then additionally braiding another layer of silver-plated copper wires or tin-plated copper

wires to form a conductive core, wrapping the conductive core with an insulation layer,

and wrapping the insulation layer with a composite shielding layer formed by composite

braiding of fibers and metal wires, wherein the insulation layer is a silicone rubber

insulation layer and has a thickness of 1-2.4mm; the composite shielding layer comprises

%-70% of metal wires, the braiding angle is controlled to 45±5, the braiding density is

greater than 80%, and the thickness of the shielding layer is 0.3mm-0.8mm; and wrapping

the composite shielding layer with a polyester belt layer;

[0029] Step 2: preparing a weak-current cable core

[0030] Mixing and concentrically stranding multiple stainless steel wires and

aramid fibers to prepare a flexible wire core, wherein the content of the armaid fibers is

%-90%, the pitch ratio is 5-10, and the cross-section of the wire core is circular; then,

winding a copper wire around the flexible wire core, wherein the copper wire is an

annealed copper wire, has a diameter of 0.12-0.3mm, and has a pitch ratio of 5-10; then,

extruding an insulation layer outside the copper wire, wherein the insulation layer is a silicone rubber insulation layer and has a thickness of 0.5-1mm; then, wrapping the insulation layer with a composite shielding layer, wherein the composite shielding layer comprises 60%-70% of metal wires and 30%-40% of fibers, the braiding angle is controlled to 45±50, the braiding density is greater than 80%, and the thickness is

0.3mm-0.8mm; and wrapping the outer surface of the composite shielding layer with a

polyester belt layer;

[0031] Step 3: forming a cable

[0032] Combining the cable cores prepared in Step 1 and Step 2 to form a cable,

wherein three charging cable cores are distributed in a regular triangle, every two of the

three charging cable cores are tangent to each other, and three weak-current cable cores

are distributed in an inverted regular triangle and are located in gaps between the tangent

charging cable cores; wrapping the six cable cores with a polyester belt layer with a

thickness of 0.3-0.4mm; and filling gaps between the six cable cores with fillers;

[0033] Step 4: after the cable is formed, wrapping the polyester belt layer with an

overall shielding layer, wherein the overall shielding layer is a composite shielding layer

which comprise 60%-70% of metal wires and 30%-40% of fibers, the braiding angle is

controlled to 45±5°, the braiding density is greater than 80%, and the thickness is

0.04-0.2mm;

[0034] Step 5: wrapping the composite shielding layer with an isolation layer,

wherein the isolation layer is a PVC isolation layer or a PEX isolation layer, and has a

thickness of 0.8-2mm;

[0035] Step 6: wrapping the isolation layer with a braided layer, wherein the

braided layer is an aramid braided layer, has a thickness of 0.05-0.2mm, and has a braiding

density greater than 80%;

[0036] Step 7: extruding a PVC-rubber mixture outside the braided layer to form

an outer sheath layer on the braided layer, wherein the thickness of the outer sheath layer is 1-3mm; and in the extrusion process, the PVC-rubber mixture is mixed with aluminum oxide or silicon carbide wear-resistant particles and graphite powder, the particle size of the wear-resistant particles is 40-60nm, and the particle size of the graphite powder is

-40nm.

[0037] Preferably, the flexible wire core in Step 2 is prepared by means of an

integrated stranding device which comprises a base plate, wherein an electric slider is

mounted on the base plate, a moving frame is mounted on the electric slider, a rotary

motor is mounted on the moving frame through a motor base, a stranding mechanism is

arranged on an output shaft of the rotary motor, a lead frame is arranged in the middle of

the base plate, and a guide mechanism is arranged at the rear end of the base plate; the

lead frame is a cavity structure and is in a horn shape with the diameter becoming larger

gradually in an axial direction;

[0038] The stranding mechanism comprises a rotary stranding frame mounted on

the output shaft of the rotary motor, stranding lantern rings are arranged on the rotary

stranding frame, stranding lock grooves are symmetrically formed in an upper side and a

lower side of the rotary stranding frame, slots are symmetrically formed in side walls of

the stranding lantern rings, fastening covers are arranged on the stranding lantern rings,

through holes are formed in middle portions of the fastening covers, and the thickness of

outer walls of the fastening covers becomes larger gradually from left to right;

[0039] The guide mechanism comprises a guide plate mounted on the base plate,

wherein guide holes are symmetrically formed in the guide plate, guide frames matched

with the guide holes are arranged on the guide plate, guide rollers are arranged on lower

sides of front ends of the guide frames through bearings, and lock holes are formed in

upper sides of the guide frames; a bidirectional drive cylinder is mounted on a side wall of

the guide plate, lock blocks are arranged on the bidirectional drive cylinder, and stranding

grooves are formed in the lock blocks;

[0040] A telescopic tube is mounted on the side wall of the guide plate, a

telescopic hole is formed in the telescopic tube, a telescopic frame is arranged in the

telescopic hole in a sliding fit manner, a telescopic spring is arranged between the

telescopic frame and an inner wall of the telescopic hole, an execution motor is mounted

in the telescopic tube through a motor base, an execution cam is arranged on an output

shaft of the execution motor and abuts against the telescopic frame, and an execution

block is arranged on the telescopic frame and is a cone structure with the diameter being

larger gradually from left to right; buffer grooves are regularly formed in the execution

block in a circumferential direction, and buffer plates are arranged in the buffer grooves

through springs;

[0041] The stranding process comprises the following steps: enabling aramid

fibers and stainless steel wires to sequentially penetrate through the guide holes, the guide

frames, the lead frame, the slots and the stranding lock grooves, and decreasing the

distance between the aramid fibers and the stainless steel wires by the lead frame to

control stranded points of the aramid fibers and the stainless steel wires within the guide

frame; then, fastening the fastening covers, and locking left ends of the aramid fibers and

the stainless steel wires through the cooperation of the fastening covers and the stranding

lock grooves; controlling, by the rotary motor, the rotary stranding frame to rotate to drive

the aramid fibers and the stainless steel wires to be stranded; and at the same time,

controlling, by the elastic slider, the moving frame to move from right to right at a

constant speed in the stranding process, such that the aramid fibers and the stainless steel

wires are driven to move synchronously from right to left;;

[0042] In the stranding process, the execution motor controls the execution cam to

rotate, the execution cam is matched with the telescopic spring to control the execution

block to operate, the execution block and the lead frame interact enable the execution

block to move to be inserted into the lead frame to knock the stranded points of the aramid fibers and the stainless steel wires, such that the stranding tightness of the aramid fibers and the stainless steel wires is guaranteed.

[0043] Preferably, in the integrated stranding device, the buffer grooves are

regularly formed in the execution block in the circumferential direction, and the buffer

plates are arranged in the buffer grooves through the springs; wherein, in the stranding

process, the buffer grooves guide to-be-stranded portions of the aramid fibers and the

stainless steel wires during operation, such that the frictional force with the execution

block is reduced with the aid of the buffer plates and the springs when the amarid fibers

and the stainless steel wires are knocked.

[0044] According to the solution of the invention, a stranding device for a

weak-current flexible wire core is further provided and comprises a base plate, an electric

slider, a moving frame, a lead frame, a rotary motor, a stranding mechanism, a guide

mechanism and an execution motor, wherein:

[0045] The electric slider is mounted on the base plate, the moving frame is

mounted on the electric slider, and the rotary motor is mounted on the moving frame

through a motor base; the stranding mechanism is arranged on an output shaft of the rotary

motor;

[0046] The lead frame is arranged in the middle of the base plate; the guide

mechanism is arranged at the rear end of the base plate; the lead frame is of a cavity

structure and is in a horn shape with the diameter becoming larger gradually in an axial

direction;

[0047] The stranding mechanism comprises a rotary stranding frame mounted on

the stranding lantern rings, fastening covers are arranged on the stranding lantern rings, through holes are formed in middle portions of the fastening covers, and the thickness of outer walls of the fastening covers becomes larger gradually from left to right;

[0048] The guide mechanism comprises a guide plate mounted on the base plate,

grooves are formed in the lock blocks;

[0049] A telescopic tube is mounted on the side wall of the guide plate, a

through springs;

[0050] The buffer grooves are regularly formed in the execution block in the

circumferential direction, and the buffer plates are arranged in the buffer grooves through

the springs; wherein, in the stranding process, the buffer grooves guide to-be-stranded

portions of aramid fibers and stainless steel wires during operation, such that the frictional

force with the execution block is reduced with the aid of the buffer plates and the springs

when the amarid fibers and the stainless steel wires are knocked.

[0051] From the above technical solution of the invention, the invention has the following beneficial effects:

[0052] 1. Because of the high tensile strength and initial modulus of aramid fibers,

the flexible center of traditional cables is made of the aramidfibers; however, the ductility

and heat resistance of the aramid fibers are low, and the quality of the flexible wire core

has a direct influence on the quality of the cables; the stranding tightness of the flexible

wire core prepared through traditional preparation methods by mixing and stranding

aramid fibers and stainless steel wires cannot be guaranteed, which directly affects the

using effect of the cables. In the invention, the flexible center formed by stranding aramid

fibers with high strength and tenacity and composites of stainless steel with good heat

resistance and a high modulus is good in temperature resistance, high in modulus, good in

ductility and better in bend resistance;

[0053] 2. The copper wire is wound around the flexible center to realize

small-pitch regular stranding, such that the bend resistance of the weak-current wire core

is further improved;

[0054] 3. The weak-current wire core and a composite shield device in the overall

shielding layer can shield signal disturbance, and the bend resistance is further improved

by means of metal wires and fibers which are braided together;

[0055] 4. The outer sheath layer adopts a composite mixture mixed with particles

that can enhance the wear resistance and tensile property of cables, such that the service

life of the cables is prolonged;

[0056] 5. Considering that traditional charging copper conductors are too hard, a

layer of silver-plated copper wires or tin-plated copper wires is additionally braided after

multiple silver-plated copper wires or tin-plated copper wires are stranded, such that the

conductor is prevented from becoming loose, and the flexibility of the conductor is

improved;

[0057] 6. Compared with the aramid braided structure of traditional flexible wire cores, the invention adopts an efficient stranding device to ensure the standing tightness of aramid fibers and stainless steel wires in the wire core; moreover, the aramid fibers and the stainless steel wires will not be worn under the effect of an external force under the precondition that the stranding tightness of the aramid fibers and the stainless steel wires is guaranteed.

[0058] It should be understood that all combinations obtained based on the above

concepts and the concepts described in further detail below without any contradictions

should be construed as one part of the subject matter of the invention

[0059] The above and other aspects, embodiments and features of the invention

can be understood more comprehensively from the following description in conjunction

with accompanying drawings. Other additional aspects such as the features and/or

beneficial effects of illustrative embodiments of the invention will be made clearer in the

following description, or can be known according to specific embodiments of the

invention.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0060] The drawings are not drawn to scale. In the drawings, the same or similar

constituent parts illustrated in the figures are represented by the same reference sign. For

the sake of clarity, not all constituent parts are marked out. Herein, the embodiments of the

invention will be described with reference to examples and accompanying drawings,

wherein:

[0061] FIG. 1 is a sectional view of a cable for charging piles for electric vehicles

according to the invention;

[0062] FIG. 2 is a schematic diagram of a weak-current cable core of the cable for

charging piles for electric vehicles according to the invention;

[0063] FIG. 3 is a preparation flow diagram of the cable for charging piles for electric vehicles according to the invention;

[0064] FIG. 4 is a sectional view of a stranding device according to the invention;

[0065] FIG. 5 is a structural diagram of the stranding device according to the

invention;

[0066] FIG. 6 is a sectional view of an execution block of the stranding device

according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0067] To gain a better understanding of the technical contents of the invention,

the invention will be explained below in conjunction with the following specific

embodiments and the figures 1-6.

[0068] In this disclosure, all aspects of the invention will be described with

reference to the accompanying drawings, in which many embodiments of the invention are

illustrated. The embodiments in this disclosure are not intended to include all the aspects

of the invention. It should be understood that many concepts and embodiments introduced

above and those concepts and embodiments described in further detail below may be

implemented in any one of many manners because the concepts and embodiments

disclosed by the invention are not limited to any implementation. In addition, some

aspects disclosed by the invention can be used separately, or be used in combination with

any other aspects disclosed by the invention.

[0069] [Embodiment 1 - cable and cable preparation]

[0070] As shown in FIG. 1 and FIG. 2, in a first aspect, the invention discloses a

cable for charging piles for electric vehicles. The cable comprises cable cores, a polyester

belt layer 30 wrapping the cable cores, an overall shielding layer 40 wrapping the

polyester belt layer 30, an isolation layer 50 wrapping the composite shielding layer 40, a

braided layer 60 wrapping the isolation layer 50, an outer sheath layer 80 arranged outside the braided layer 60, and a filling layer 90 filled between charging cable cores 10 and weak-current cable cores 20 and wrapped with the polyester belt layer 30.

[0071] The outer sheath layer 80 is formed by extruding a PVC-rubber mixture on

the braided layer, and has a thickness of 1-3mm. The filling layer 90 adopts nylon fillers

for filling.

[0072] As shown in FIG. 1 and FIG. 2, the cable cores include the charging cable

cores 10 (strong-current cable cores) and the weak-current cable cores 20, and the

charging cable cores 10 are configured as electric energy transmission media between

charging piles and electric vehicles. The weak-current cable cores 20 are configured as

signal cable cores and control cable cores which are of the same structure. The multiple

charging cable cores 10 and the multiple weak-current cable cores 20 are distributed in a

manner that every two of the charging cable cores 10 and the weak-current cable cores 20

are tangent to each other.

[0073] Referring to FIG. 1 and FIG. 2, three charging cable cores are distributed in

a regular triangle, and every two of the three charging cable cores are tangent to each other;

and three weak-current cable cores are distributed in an inverted regular triangle and are

located in gaps between the tangent charging cable cores, such that a symmetrical

structure is formed.

[0074] In a preferred example, each weak-current cable core 20 comprises a

flexible wire core 21 and a copper wire 22 wound around the flexible wire core 21,

wherein the flexible wire core 21 is formed by mixing and concentrically stranding aramid

fibers and a stainless steel wires, wherein the content of the aramid fibers is 80%-90%,

and the pitch ratio is 5-10. An insulation layer 23 is extruded outside the copper wire 22

and is wrapped with a composite shielding layer 24 formed by braiding metal wires and

fibers. The composite shielding layer 24 is wrapped with a polyester belt layer 25. The

weak-current cable core, formed by the flexible wire core (flexible center) and the copper wire wound around the flexible wire core, has good bend resistance.

[0075] In a particularly preferred example, the composite shielding layer 24

comprises 60%-70% of metal wires, the braiding angle is controlled to 45±5, the braiding

density is greater than 80%, and the thickness is 0.3mm-0.5mm. During the test process,

after a bend test is carried out 5000 times on the weak-current cable core 20 and the cable

adopting such cable cores 20 in the above embodiment under an ambient temperature of

E, the weak-current cable core 20 and the cable are still in a good condition and

maintain good electrical contact, the surface of the outer sheath layer is free of cracks, and

the heat resistance and the bend resistance are good.

[0076] Meanwhile, during the test process, after a simulated pressure test is carried

out on the cable 10,000 times respectively with a IT pressure load (corresponding to

micro and compact electric vehicles and hybrid electric vehicles such as AO and Al) and a

2T pressure load (corresponding to medium-high grade electric vehicles and hybrid

electric vehicles), the cable can still recover after the pressure is released, and can

guarantee good electrical contact.

[0077] In a preferred embodiment, the outer sheath layer 30 is a polyester belt

covering which has a thickness of 0.04-0.2mm.

[0078] In a preferred embodiment, the insulation layer of the weak-current cable

core 20 is a silicone rubber insulation layer, and has a thickness of 0.5-1mm.

[0079] In a preferred embodiment, the isolation layer 50 is a PVC isolation layer,

or a PE or PO isolation layer, and has a thickness of 0.8-2mm.

[0080] In a preferred embodiment, the braided layer 60 is an aramid braided layer,

has a thickness of 0.05-0.2mm, and has a braiding density greater than 80%.

[0081] In a preferred embodiment, in the extrusion process of the outer sheath

layer 80, the PVC-rubber mixture is mixed with aluminum oxide or silicon carbide

wear-resistant particles and graphite powder, wherein the particle size of the wear-resistant particles is 40-60nm, and the particle size of the graphite powder is 30-40nm. According to the outer sheath layer mixed with the composite mixture in this embodiment of the invention, the particles enhance the wear resistance and tensile property of the cable and prolong the service life of the cable.

[0082] [Embodiment 2 - cable preparation process]

[0083] As shown in FIG. 1 and FIG. 3, the embodiments of the invention further

provide a preparation method of a cable for charging piles for electric vehicles, comprising

the following steps:

[0084] Step 1: a charging cable core is prepared

[0085] Multiple silver-plated copper wires or tin-plated copper wires are stranded

and then another layer of silver-plated copper wires or tin-plated copper wires is

additionally braided to form a conductive core, the conductive core is wrapped with an

insulation layer, and the insulation layer is wrapped with a composite shielding layer

formed by composite braiding of fibers and metal wires, wherein the insulation layer is a

silicone rubber insulation layer and has a thickness of 1-2.4mm; the composite shielding

layer comprises 60%-70% of the metal wires, the braiding angle is controlled to 45±5,

the braiding density is greater than 80%, and the thickness of the shielding layer is

0.3mm-0.8mm; and the composite shielding layer is wrapped with a polyester belt layer;

[0086] Step 2: a weak-current cable core is prepared

[0087] Multiple stainless steel wires are mixed with aramid fibers and are

concentrically stranded to prepare flexible wire core with a circular cross-section, wherein

the content of the armaid fibers is 80%-90%, and the pitch ratio is 5-10; then, a copper

wire is wound around the flexible wire core, wherein the copper wire is an annealed

copper wire, has a diameter of 0.12-0.3mm, and has a pitch ratio of 5-10; then, an

insulation layer is extruded outside the copper wire, wherein the insulation layer is a

silicon rubber insulation layer and has a thickness of 0.5-1mm; then, the insulation layer is wrapped with a composite shielding layer, wherein the composite shielding layer comprises 60%-70% of metal wires and 30%-40% of fibers, the braiding angle is controlled to 45±50, the braiding density is greater than 80%, and the thickness is

0.3mm-0.8mm; and the outer surface of the composite shielding layer is wrapped with a

polyester belt layer;

[0088] Step 3: a cable is formed

[0089] The cable cores prepared in Step 1 and Step 2 are combined to form a cable,

wherein three charging cable cores are distributed in a regular triangle, and every two of

the three charging cable cores are tangent to each other; three weak-current cable cores are

distributed in an inverted regular triangle and are located in gaps between the tangent

charging cable cores; and the six cable cores are wrapped with a polyester belt layer with a

thickness of 0.3-0.4mm; and gaps between the six cable cores are filled with fillers;

[0090] Step 4: after the cable is formed, the polyester belt layer is wrapped with an

overall shielding layer 40 which is a composite shielding layer, wherein the composite

shielding layer comprise 60%- 7 0% of metal wires and 30%-40% of fibers, the braiding

angle is controlled to 45±5°, the braiding density is greater than 80%, and the thickness is

0.04-0.2mm;

[0091] Step 5: the composite shielding layer is wrapped with an isolation layer,

thickness of 0.8-2mm;

[0092] Step 6: the isolation layer is wrapped with a braided layer, wherein the

density greater than 80%.

[0093] Step 7: a PVC-rubber mixture is extruded outside the braided layer to form

an outer sheath layer on the braided layer, wherein the thickness of the outer sheath layer

is 1-3mm; and in the extrusion process, the PVC-rubber mixture is mixed with aluminum oxide or silicon carbide wear-resistant particles and graphite powder, the particle size of the wear-resistant particles is 40-60nm, and the particle size of the graphite powder is

-40nm.

[0094] [Embodiment 3 - preparation of flexible wire core]

[0095] As shown in FIG. 3-FIG. 6, in preparation process of the cable of the

invention, a special integrated stranding device is used for stranding when the flexible

wire core is prepared, so as to improve the wear resistance and tensile property of the core

charging cable, wherein FIG. 4-FIG. 6 illustrate the schematic diagrams of the stranding

device.

[0096] Referring to FIG. 3-FIG. 6, the stranding device comprises a base plate 1

used as a stranding base, wherein an electric slider 2 is mounted on the base plate 1, a

moving frame 3 is mounted on the electric slider 2, a rotary motor 4 is mounted on the

moving frame 3 through a motor base, and a stranding mechanism 5 is arranged on an

output shaft of the rotary motor 4.

[0097] A lead frame 6 is arranged in the middle of the base plate 1, and a guide

mechanism 7 is arranged at the rear end of the base plate 1.

[0098] The stranding mechanism 5 comprises a rotary stranding frame 51 mounted

on the output shaft of the rotary motor 4, stranding lantern rings 52 are arranged on the

rotary stranding frame 51, stranding lock grooves are symmetrically formed in an upper

side and a lower side of the rotary stranding frame 51, and slots are symmetrically formed

in side walls of the stranding lantern rings 52.

[0099] Fastening covers 53 are arranged on the stranding lantern rings 52, through

holes are formed in middle portions of the fastening covers 53, and the thickness of outer

walls of the fastening covers 53 becomes larger gradually from left to right.

[00100] Fastening blocks 54 are symmetrically arranged on the outer walls of the

fastening covers 53, and optically, the fastening blocks 54 are made of plastic.

[00101] Referring to FIG. 3, when to be stranded, aramid fibers and stainless steel

wires sequentially penetrate through guide holes, guide frames 72, the lead frame 6, the

slots and the stranding lock grooves. The distance between the aramid fibers and the

stainless steel wires can be decreased by the lead frame 6 to control stranded points of the

aramid fibers and the stainless steel wires within the lead frame 6, such that the tightness

of the aramid fibers and the stainless steel wires in the stranding process is improved.

[00102] Then, the fastening covers 53 are fastened and are matched with the

stranding lock grooves to lock the left ends of the aramid fibers and the stainless steel

wires to ensure that the aramid fibers and the stainless steel wires can be smoothly

stranded. The rotary stranding frame 51 is controlled by the rotary motor 4 to rotate to

drive the aramid fibers and the stainless steel wires to be stranded, and the electric slider 2

controls the moving frame 3 to move from right to right at a constant speed in the

stranding process, such that the aramid fibers and the stainless steel wires are driven to

move synchronously from right to left.

[00103] The lead frame 6 is a cavity structure and is in a horn shape with the

diameter becoming larger gradually from left to right.

[00104] The guide mechanism 7 comprises a guide plate 71 mounted on the base

plate 1, wherein the guide holes are symmetrically formed in the guide plate 71, guide

frames 72 matched with the guide holes are arranged on the guide plate 71, guide rollers

73 are arranged on lower sides of front ends of the guide frames 72 through bearings, and

lock holes are formed in upper sides of the guide frames 72.

[00105] Referring to FIG. 4, a bidirectional drive cylinder 74 is mounted on a side

wall of the guide plate 71, lock blocks 75 are arranged on the bidirectional drive cylinder

74, stranding grooves are formed in the lock blocks 75, and the aramid fibers and the

stainless steel wires penetrate through the guide frames 72 and the guide rollers 73 to be

limited and guided, such that the aramid fibers and the stainless steel wires will not shake drastically under the effect of an external force in the stranding process.

[00106] The bidirectional drive cylinder 74 controls the lock blocks 75 to be

matched with the lock holes to limit the aramid fibers and stainless steel wires in the

stranding process, such that the frictional force between the aramid fibers and the guide

frames 72 is improved, and the araimd fibers and the stainless steel fibers can be

efficiently stranded.

[00107] Preferably, referring to FIG. 4 and FIG. 5, a telescopic tube 76 is mounted

on the side wall of the guide plate 71, a telescopic hole is formed in the telescopic tube 76,

a telescopic frame 77 is arranged in the telescopic hole in a sliding fit manner, a telescopic

spring 78 is arranged between the telescopic frame 77 and an inner wall of the telescopic

hole, an execution motor 79 is mounted in the telescopic tube 76 through a motor base, an

execution cam 710 is arranged on an output shaft of the execution motor 79 and abuts

against the telescopic frame 77, and an execution block 7a is arranged on the telescopic

frame 77.

[00108] Preferably, the execution block 7a is a cone structure with the diameter

being larger gradually from left to right, buffer grooves are regularly formed in the

execution block 7a in a circumferential direction, buffer plates 7b are arranged in the

buffer grooves through springs, the execution motor 79 controls the execution cam 710 to

rotate, the execution cam 710 is matched with the telescopic spring 78 to control the

execution block 7a to operate, the execution block 7a can be matched with the lead frame

6 and can move to be inserted into the lead frame 6 to knock the stranded points of the

aramid fibers and the stainless steel wires, such that the stranding tightness of the aramid

fibers and the stainless steel wires is guaranteed; the buffer grooves can guide

to-be-stranded portions of the aramid fibers and the stainless steel wires during operation,

and the frictional force with the execution block 7a can be reduced with the aid of the

buffer plates 7b and the springs when the amarid fibers and the stainless steel wires are knocked, such that the amarid fibers and the stainless steel wires will not be worn under the effect of an external force during operation under the precondition that the straining tightness of the amarid fibers and the stainless steel wires is guaranteed, and thus, the quality of the strong-current cable core is improved.

[00109] Although the invention has been disclosed above with reference to the

preferred embodiments, these preferred embodiments are not intended to limit the

invention. Those commonly skilled in the art can make different modifications and

embellishments without departing from the spirit and scope of the invention. Thus, the

protection scope of the invention should be defined by the claims.

Claims

WHAT IS CLAIMED IS:

1. A cable for charging piles for electric vehicles, comprising cable cores including a

charging cable core (10) and a weak-current cable core (20), wherein the charging cable

core (10) is configured as an electric energy transmission medium between charging piles

and electric vehicles, the weak-current cable core (20) is configured as a signal cable core

or a control cable core of a same structure, and multiple said charging cable cores (10) and

multiple said weak-current cable cores (20) are distributed in a manner that every two of

the charging cable cores (10) and the weak-current cable cores (20) are tangent to each

other;

a polyester belt layer (30) wrapping the cable cores;

an overall shielding layer (40) wrapping the polyester belt layer (30);

an isolation layer (50) wrapping the overall shielding layer (40);

a braided layer (60) wrapping the isolation layer (50); and

an outer sheath layer (80) arranged outside the braided layer (60); and a filling layer

(90) filled between the charging cable cores (10) and the weak-current cable cores (20)

and wrapped with the polyester belt layer (30);

wherein, the weak-current cable core (20) comprises a flexible wire core (21) and a

copper wire (22) wound around the flexible wire core (21), and the flexible wire core (21)

is formed by mixing and concentrically stranding aramid fibers and stainless steel wires,

wherein the content of the aramid fibers is 80%-90%, and a pitch ratio is 5-10;

an insulation layer (23) is extruded outside the copper wire (22);

the insulation layer is wrapped with a composite shielding layer (24) braided from

metal wires and fibers;

the composite shielding layer (24) is wrapped with a polyester belt layer (25);

the composite shielding layer (24) comprises 60%- 7 0% of metal wires, a braiding

angle is controlled to 45±5, a braiding density is greater than 80%, and a thickness of the shielding layer is 0.3mm-0.5mm; the charging cable core (10) is formed by additionally braiding a layer of silver-plated copper wires or tin-plated copper wires after multiple silver-plated copper wires or tin-plated copper wires are stranded.

2. The cable for charging piles for electric vehicles according to Claim 1, wherein a

thickness of the polyester belt layer (30) is 0.04-0.2mm.

3. The cable for charging piles for electric vehicles according to Claim 1, wherein the

insulation layer of the weak-current cable core (20) is a silicone rubber layer with high

tear resistance, and has a thickness of 0.5-1mm.

4. The cable for charging piles for electric vehicles according to Claim 1, wherein the

isolation layer (50) is a PVC isolation layer, or a PE or PO isolation layer, and has a

thickness of 0.8-2mm.

5. The cable for charging piles for electric vehicles according to Claim 1, wherein the

braided layer is an aramid braided layer, has a thickness of 0.3-0.5mm, and has a braiding

density greater than 80%.

6. The cable for charging piles for electric vehicles according to Claim 1, wherein the

outer sheath layer (80) is formed by extruding a PVC-rubber mixture on the braided layer,

and has a thickness of 1-3mm;

in the extrusion process of the outer sheath layer (80), the PVC-rubber mixture is

mixed with aluminum oxide or silicon carbide wear-resistant particles and graphite

powder, a particle size of the wear-resistant particles is 40-60nm, and a particle size of the

graphite powder is 30-40nm.

7. A preparation method of a cable for charging piles for electric vehicles, comprising

the following steps:

Step 1: preparing a charging cable core

stranding multiple silver-plated copper wires or tin-plated copper wires and then additionally braiding another layer of silver-plated copper wires or tin-plated copper wires to form a conductive core, wrapping the conductive core with an insulation layer, and wrapping the insulation layer with a composite shielding layer formed by composite braiding of fibers and metal wires, wherein the insulation layer is a silicone rubber insulation layer and has a thickness of 1-2.4mm; the composite shielding layer comprises

%-70% of metal wires, a braiding angle is controlled to 45±5, a braiding density is

greater than 80%, and a thickness of the shielding layer is 0.3mm-0.8mm; and wrapping

the composite shielding layer with a polyester belt layer;

Step 2: preparing a weak-current cable core

mixing and concentrically stranding multiple stainless steel wires and aramid fibers to

prepare a flexible wire core, wherein the content of the armaid fibers is 80%-90%, a pitch

ratio is 5-10, and a cross-section of the wire core is circular; then, winding a copper wire

around the flexible wire core, wherein the copper wire is an annealed copper wire, has a

diameter of 0.12-0.3mm, and has a pitch ratio of 5-10; then, extruding an insulation layer

outside the copper wire, wherein the insulation layer is a silicone rubber insulation layer

and has a thickness of 0.5-1mm; then, wrapping the insulation layer with a composite

shielding layer, wherein the composite shielding layer comprises 60%- 7 0% of metal wires

and 30%-40% of fibers, a braiding angle is controlled to 45±5°, a braiding density is

greater than 80%, and a thickness is 0.3mm-0.8mm; and wrapping an outer surface of the

composite shielding layer with a polyester belt layer;

Step 3: forming a cable

combining the cable cores prepared in Step 1 and Step 2 to form a cable, wherein three

said charging cable cores are distributed in a regular triangle, every two of the three

charging cable cores are tangent to each other, and three said weak-current cable cores are

charging cable cores; wrapping the six cable cores with a polyester belt layer with a thickness of 0.3-0.4mm; and filling gaps between the six cable cores with fillers;

Step 4: after the cable is formed, wrapping the polyester belt layer with an overall

shielding layer, wherein the overall shielding layer is a composite shielding layer which

comprise 60%-70% of metal wires and 30%-40% of fibers, a braiding angle is controlled

to 45±50, a braiding density is greater than 80%, and a thickness is 0.04-0.2mm;

Step 5: wrapping the composite shielding layer with an isolation layer, wherein the

isolation layer is a PVC isolation layer or a PEX isolation layer, and has a thickness of

0.8-2mm;

Step 6: wrapping the isolation layer with a braided layer, wherein the braided layer is

an aramid braided layer, has a thickness of 0.05-0.2mm, and has a braiding density greater

than 80%;

Step 7: extruding a PVC-rubber mixture outside the braided layer to form an outer

sheath layer on the braided layer, wherein a thickness of the outer sheath layer is 1-3mm;

and in the extrusion process, the PVC-rubber mixture is mixed with aluminum oxide or

silicon carbide wear-resistant particles and graphite powder, a particle size of the

wear-resistant particles is 40-60nm, and a particle size of the graphite powder is 30-40nm.

8. The preparation method of a cable for charging piles for electric vehicles according

to Claim 7, wherein the flexible wire core in Step 2 is prepared by means of an integrated

stranding device which comprises a base plate, an electric slider is mounted on the base

plate, a moving frame is mounted on the electric slider, a rotary motor is mounted on the

moving frame through a motor base, a stranding mechanism is arranged on an output shaft

of the rotary motor, a lead frame is arranged in a middle of the base plate, and a guide

mechanism is arranged at a rear end of the base plate; the lead frame is a cavity structure

and is in a horn shape with a diameter becoming larger gradually in an axial direction;

the stranding mechanism comprises a rotary stranding frame mounted on the output

shaft of the rotary motor, stranding lantern rings are arranged on the rotary stranding frame, stranding lock grooves are symmetrically formed in an upper side and a lower side of the rotary stranding frame, slots are symmetrically formed in side walls of the stranding lantern rings, fastening covers are arranged on the stranding lantern rings, through holes are formed in middle portions of the fastening covers, and a thickness of outer walls of the fastening covers becomes larger gradually from left to right; the guide mechanism comprises a guide plate mounted on the base plate, guide holes are symmetrically formed in the guide plate, guide frames matched with the guide holes are arranged on the guide plate, guide rollers are arranged on lower sides of front ends of the guide frames through bearings, and lock holes are formed in upper sides of the guide frames; a bidirectional drive cylinder is mounted on a side wall of the guide plate, lock blocks are arranged on the bidirectional drive cylinder, and stranding grooves are formed in the lock blocks; a telescopic tube is mounted on the side wall of the guide plate, a telescopic hole is formed in the telescopic tube, a telescopic frame is arranged in the telescopic hole in a sliding fit manner, a telescopic spring is arranged between the telescopic frame and an inner wall of the telescopic hole, an execution motor is mounted in the telescopic tube through a motor base, an execution cam is arranged on an output shaft of the execution motor and abuts against the telescopic frame, and an execution block is arranged on the telescopic frame and is a cone structure with a diameter being larger gradually from left to right; buffer grooves are regularly formed in the execution block in a circumferential direction, and buffer plates are arranged in the buffer grooves through springs; the stranding process comprises the following steps: enabling aramid fibers and stainless steel wires to sequentially penetrate through the guide holes, the guide frames, the lead frame, the slots and the stranding lock grooves, and decreasing a distance between the aramid fibers and the stainless steel wires by the lead frame to control stranded points of the aramid fibers and the stainless steel wires within the guide frame; then, fastening the fastening covers, and locking left ends of the aramid fibers and the stainless steel wires through the cooperation of the fastening covers and the stranding lock grooves; controlling, by the rotary motor, the rotary stranding frame to rotate to drive the aramid fibers and the stainless steel wires to be stranded; and at the same time, controlling, by the elastic slider, the moving frame to move from right to right at a constant speed in the stranding process, such that the aramid fibers and the stainless steel wires are driven to move synchronously from right to left; in the stranding process, the execution motor controls the execution cam to rotate, the execution cam is matched with the telescopic spring to control the execution block to operate, the execution block and the lead frame interact enable the execution block to move to be inserted into the lead frame to knock the stranded points of the aramid fibers and the stainless steel wires, such that the stranding tightness of the aramid fibers and the stainless steel wires is guaranteed.

9. The preparation method for a cable for charging piles for electric vehicles according

to Claim 8, wherein in the integrated stranding device, the buffer grooves are regularly

formed in the execution block in the circumferential direction, and the buffer plates are

arranged in the buffer grooves through the springs; wherein, in the stranding process, the

buffer grooves guide to-be-stranded portions of the aramid fibers and the stainless steel

wires during operation, such that a frictional force with the execution block is reduced

with the aid of the buffer plates and the springs when the amarid fibers and the stainless

steel wires are knocked

10. A stranding device for a weak-current flexible wire core of a cable for charging

piles for electric vehicles, comprising a base plate, an electric slider, a moving frame, a

lead frame, a rotary motor, a stranding mechanism, a guide mechanism and an execution

motor, wherein:

the electric slider is mounted on the base plate, the moving frame is mounted on the electric slider, and the rotary motor is mounted on the moving frame through a motor base; the stranding mechanism is arranged on an output shaft of the rotary motor; the lead frame is arranged in a middle of the base plate; the guide mechanism is arranged at a rear end of the base plate; the lead frame is of a cavity structure and is in a horn shape with a diameter becoming larger gradually in an axial direction; the stranding mechanism comprises a rotary stranding frame mounted on the output shaft of the rotary motor, stranding lantern rings are arranged on the rotary stranding frame, stranding lock grooves are symmetrically formed in an upper side and a lower side of the rotary stranding frame, slots are symmetrically formed in side walls of the stranding lantern rings, fastening covers are arranged on the stranding lantern rings, through holes are formed in middle portions of the fastening covers, and a thickness of outer walls of the fastening covers becomes larger gradually from left to right; the guide mechanism comprises a guide plate mounted on the base plate, guide holes are symmetrically formed in the guide plate, guide frames matched with the guide holes are arranged on the guide plate, guide rollers are arranged on lower sides of front ends of the guide frames through bearings, and lock holes are formed in upper sides of the guide frames; a bidirectional drive cylinder is mounted on a side wall of the guide plate, lock blocks are arranged on the bidirectional drive cylinder, and stranding grooves are formed in the lock blocks; a telescopic tube is mounted on the side wall of the guide plate, a telescopic hole is formed in the telescopic tube, a telescopic frame is arranged in the telescopic hole in a sliding fit manner, a telescopic spring is arranged between the telescopic frame and an inner wall of the telescopic hole, an execution motor is mounted in the telescopic tube through a motor base, an execution cam is arranged on an output shaft of the execution motor and abuts against the telescopic frame, and an execution block is arranged on the telescopic frame and is a cone structure with a diameter being larger gradually from left to right; buffer grooves are regularly formed in the execution block in a circumferential direction, and buffer plates are arranged in the buffer grooves through springs; the buffer grooves are regularly formed in the execution block in the circumferential direction, and the buffer plates are arranged in the buffer grooves through the springs; wherein, in a stranding process, the buffer grooves guide to-be-stranded portions of aramid fibers and stainless steel wires during operation, such that a frictional force with the execution block is reduced with the aid of the buffer plates and the springs when the amarid fibers and the stainless steel wires are knocked.

14 10 17 Mar 2021

13 12 30 11 80 \ \ 60 50 40 2021101392

N

20

90

FIG. 1

1/5

23

21 24 25

2/5 FIG. 2

Prepare a charging 充电电芯制备 17 Mar 2021

cable core

Prepare a 弱电电芯制备 weak-current cable

Form 组合成缆a cable 2021101392

Wrap an overall 总屏蔽层绕包 shielding layer

Wrap the composite shielding 复合屏蔽层外包覆隔离层 layer with an isolation layer

Wrap the isolation layer with a 隔离层外包覆编织层 braided layer

Extrude a PVC-rubber mixture outside the braided layer to form 在编织层外采用聚氯乙烯-橡胶混合物挤包形成外护套层 an outer sheath layer

FIG. 3

3/5